Sen. Barack Obama promised Sunday he would make immigration reform a top priority of his first year in office if he is elected president as he chided Republican John McCain for backing away from his own comprehensive immigration bill.

Obama addressed the four-day National Council of La Raza convention, which has attracted more than 20,000 people to the San Diego Convention Center. McCain, a senator from Arizona and the Republican presidential nominee-in-waiting, will address the convention Monday.

“I know Senator McCain used to buck his party on immigration in fighting for comprehensive reform and I admired him for it and joined him in it,” Obama said in his speech. “But when he was running for his party's nomination, he abandoned that courageous stand and said that he wouldn't even support his own legislation if it came up for a vote.”

“I think it's time for a president who won't walk away from something as important as comprehensive reform just because it becomes politically unpopular,” the Illinois senator said. “I will make it a top priority in my first year as the president of the United States of America.”

Obama also denounced recent immigration raids.

“The system isn't working . . . when communities are terrorized by (Immigration and Customs Enforcement) immigration raids, when nursing mothers are torn from their babies, when children come home from school to find their parents missing,” he said.

Large Latino gatherings such as the National Council of La Raza convention have become a command performance for the major-party presidential candidates because Latinos loom as a potentially decisive voting bloc in the Nov. 4 election.

Obama said he supports stronger border enforcement, stiffer penalties against employers that knowingly hire people who are in the country illegally. He also favors a temporary guest worker program and an opportunity for the estimated 12 million current illegal residents to obtain citizenship as long as they pay a fine, learn English and wait in line behind legal residents.

“That way, we can reconcile our values as both a nation of immigrants and a nation of laws,” he said.

The principles Obama laid out were embodied in the immigration bill cosponsored by McCain and Sen. Edward Kennedy, D-Mass., that died in Congress in favor of a border-security-only bill backed by most Republicans. After his bill was defeated, McCain said he supported the enforcement-first approach because that's what the American people wanted.

A McCain supporter insisted Sunday that criticism of the Republican as shifting his ground on immigration was unfair.

“The reality is that Senator McCain is the one senator that basically went against his own party, took the standard-bearer for immigration reform,” said former U.S. Treasurer Rosario Marin during a McCain campaign conference call. “I think that needs to be fully recognized. Senator McCain did it at great political peril. He did what he thought was the right thing to do.”

Obama also announced support for a proposal advanced by his vanquished nomination rival, Sen. Hillary Rodham Clinton of New York, for a tax credit of up to 50 percent for small businesses providing health insurance to their employees.

“We know that small businesses are the engines of economic prosperity in our communities, especially in Latino communities,” he said.

Audience members interviewed after the speech generally liked what they heard.

Former New Mexico Gov. Jerry Apodaca said he wished Obama had addressed the war in Iraq, but was pleased with his comments on immigration.

“You still have 12 million that are here now,” he said. “They are illegal but they are here. You can't corral them and take them back.”

Others said they would like to have heard more specifics.

“I hope that what he promises is actually going to happen,” said Hector Hernandez, 57, an unemployed technology worker from Chula Vista. “He talked about health care, but how are you going to pay for that? I'd like to see some of that better developed.”

Outside, a crowd of demonstrators gathered in front of the convention center – a mix of anti-illegal immigration activists, Obama supporters and others.

San Diego police officer Joel Tien said afterward that there were as many as 460 people outside at one point, the majority of them Obama supporters, and about 60 anti-illegal immigration protesters. He said there had not been any arrests.

Tom Farber, a high school teacher who lives downtown, carried a homemade sign supporting Obama. “I think it's great, the expression,” said Farber, 46, of the protest. “This is what democracy is for.”

Farber said he favored immigration policies that would acknowledge the need for foreign workers.

“We still have the ability to have a proper immigration process that is fair,” he said. “As long as there are economic opportunities, here, they are coming, and we need them.”

Several of the protesters, who said they also planned to picket McCain's speech Monday as well, said they were opposed not only to Obama's candidacy and his position on immigration, but the National Council of La Raza.

One protester, Al Hather of Oceanside, 49, carried a picket sign depicting a cartoon boy urinating on the words “La Raza.” He said his sign was not a statement against Latinos but against the organization.

During his speech, Obama condemned the often harsh tone surrounding the immigration debate as insulting to Latinos.

“They're counting on us to stop the hateful rhetoric that is filling our airwaves – rhetoric that poisons our political discourse, degrades our democracy and has no place in this great nation,” Obama said. “They're counting on us to rise above fear and demagoguery and pettiness and partisanship and finally enact comprehensive immigration reform.”

Before his luncheon speech to La Raza, Obama attended a fundraising reception at the El Cortez Hotel where guests paid $28,500 to attend a VIP reception in the historic hotel and $2,300 for a general reception in a tent outside.

On the sidewalk outside, a small group of protesters chanted “end the occupation” just loudly enough that Obama paused in his remarks to try to make out what they were saying.

“I want to end the occupation. I do,” he said, referring to the war in Iraq. “I was trying to figure out what they were saying. I'm for that. That's why I'm running for president of the United States.”